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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Pavankumar Kondeti <pkondeti@codeaurora.org>
Subject: [for-next][PATCH 1/5] tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
Date: Tue, 13 Dec 2016 11:14:09 -0500	[thread overview]
Message-ID: <20161213161435.713332031@goodmis.org> (raw)
In-Reply-To: 20161213161408.374215860@goodmis.org

[-- Attachment #1: 0001-tracing-Use-SOFTIRQ_OFFSET-for-softirq-dectection-fo.patch --]
[-- Type: text/plain, Size: 1215 bytes --]

From: Pavankumar Kondeti <pkondeti@codeaurora.org>

The 's' flag is supposed to indicate that a softirq is running. This
can be detected by testing the preempt_count with SOFTIRQ_OFFSET.

The current code tests the preempt_count with SOFTIRQ_MASK, which
would be true even when softirqs are disabled but not serving a
softirq.

Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6f420d7b703b..970aafe80b49 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1949,7 +1949,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 #endif
 		((pc & NMI_MASK    ) ? TRACE_FLAG_NMI     : 0) |
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
-		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
 		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
 		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
 }
-- 
2.10.2

  reply	other threads:[~2016-12-13 16:15 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-13 16:14 [for-next][PATCH 0/5] tracing: Hopefully last update for merge window Steven Rostedt
2016-12-13 16:14 ` Steven Rostedt [this message]
2016-12-13 16:14 ` [for-next][PATCH 2/5] tracing/rb: Init the CPU mask on allocation Steven Rostedt
2016-12-13 16:14 ` [for-next][PATCH 3/5] tracing/kprobes: Add a helper method to return number of probe hits Steven Rostedt
2016-12-13 16:14 ` [for-next][PATCH 4/5] kprobes/trace: Fix kprobe selftest for newer gcc Steven Rostedt
2016-12-13 16:14 ` [for-next][PATCH 5/5] selftests: ftrace: Shift down default message verbosity Steven Rostedt
2016-12-13 16:30   ` Steven Rostedt

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